There is a best selling book "Be, Know, Do" which relies heavily from this book as a source. I recommend buying this book instead because it is much cheaper and contains virtually all the information contained in that one.
I wish this book was thicker with even more useful information. The book could have expounded far more in detail, especially things related to interpersonal skills (communication and motivation). I know there is a wealth of psychological research on the subject of leadership which the book could have used for further enlightenment. But the book limits its focus only on its history and military leaders as a source.
Leadership is a deep and complex subject because it requires one to deeply understand oneself and the others. This book provides a solid basis.